Fuel cell stacks are composed of a plurality of cells between end plates at both ends, in which each of the cells is composed of a membrane electrode assembly (MEA), a gas diffusion layer (GDL), and a separation plate. Hydrogen, air, and cooling water are supplied through a channel inside the separation plate and a gasket is used to seal fluid between separation plate. Since the cells in the stacks are directly associated with ohmic loss due to an increase in contact resistance and mass transfer resistance in the GDL, it is necessary to maintain an appropriate fastening force in order to achieve high performance.
The stacks that are mounted on a vehicle require high performance, so that the plurality (one hundred to three hundreds or more) of cells with around 1V are generally stacked. The stacked unit cells are pressed by the end plates and fastened vertically by one or more fastening bars. In the conventional fastening structure, fastening bars are parallel to and in contact with one side of the stacks without any locking structure. Accordingly, the fuel cell stacks may be deformed or the separation plate may be separated from a fuel cell stack during a vehicle front/rear collision. This is likely to cause problems such as a secondary electric accident or leakage of the hydrogen. Therefore, a structure for stably fastening the fuel cell stack is necessary to structural stabilization.
The description provided above as a related art of the present disclosure is just for helping in understanding the background of the present disclosure and should not be construed as being included in the related art known by those skilled in the art.